THEORY OF SURFACE ELECTRONIC STRUCTURE.

A newly developed, accurate, and unified method for calculating surfaces, the full-potential linearized augmented plane wave (FLAPW) method is described. This is a unified method in that it can easily treat not only simple metals and semiconductors but also transition-metal surfaces. It is also unified in the sense that it is capable of treating molecular absorption on surfaces and also the extreme limit of the isolated molecule and the clean surface. In this approach, which represents a major advance in that the local density equations are solved without any shape approximations to the electronic potential or electronic charge density, a new technique for solving Poisson's equation for a general charge density and potential is implemented. Results obtained for thin metal films and for nearly free molecules demonstrate the high degree of accuracy possible with this method.